A femtocell base station is designed to connect user equipment located in a femtocell to a service provider's network. A femtocell may denote a small service area covered by a femtocell base station. For example, the femtocell may be a home or a small business office in a cellular system. The range of a femtocell base station may be about 10 meters. The femtocell base station has been applied to a Long Term Evolution (LTE) communication network. The 3rd Generation Partnership Project (3GPP) has introduced standard specifications for LTE technology. In 3GPP LTE standard specifications, the femtocell base station as well as a macrocell base station is defined. The femtocell base station may be referred to as a Home NodeB (HNB) for a 3G femtocell or as a Home Evolved Node Base station (HeNB) for an LTE femtocell. The macrocell base station may be referred to as an evolved NodeB (eNB).
The 3GPP LTE standard specifications define three access control modes of a femtocell base station. The access control mode may enable a femtocell base station to control access of user equipment. The access control mode may include an open access mode, a closed subscriber group (CSG) access mode, and a hybrid access mode. An open mode femtocell base station, operated in the open access mode, unconditionally allows user equipment to access and to use resources thereof. A CSG mode femtocell base station, operated in a CSG access mode, allows user equipment belonging to a related CSG to access and to use resources thereof. The CSG may be a group of user equipment that is allowed to access to one specific femtocell or a group of femtocells. A hybrid mode femtocell base station, operated in a hybrid access mode, first allows access of user equipment belonging to a related CSG. Such user equipment may be referred to as CSG-member user equipment. If the hybrid mode femtocell base station has available resources after allowing the CSG-member user equipment, the hybrid mode femtocell base station allows user equipment not belonging to the related CSG. Such user equipment may be referred to as non-CSG member user equipment.
As described above, a femtocell base station, operated in a CSG access mode or a hybrid access mode, may restrict non-CSG member user equipment from accessing the femtocell base station. The access control mode simply restricts user equipment from accessing a corresponding femtocell base station. Such a restriction policy generally creates inconvenience for many users. For example, non-CSG member user equipment, such as a visitor's user equipment, generally desires access to a public Internet network through a femtocell base station operated in a CSG access mode or a hybrid access mode. In this case, non-CSG member user equipment cannot access the public Internet network because it is restricted from accessing the femtocell base station.